题干
—_______ My father bought a new computer for me.
—Really?
A：What's wrong?
B：Guess what?
C：Hurry up!
D：Nice idea!
答案(点此获取答案解析）
B
—_______ My father bought a new computer for me.
—Really?
A：What's wrong?
B：Guess what?
C：Hurry up!
D：Nice idea!
，
表示不超过
的最大整数，如
. 定义
上的函数
，若
，则
中所有元的和为（ ）
